Spark plugs are used in internal combustion engines to ignite an air/fuel mixture. The spark plug is generally mounted in the cylinder head of the engine so that the firing tip is in a combustion chamber. A conventional spark plug includes a ceramic body which serves as an insulator between a center electrode and an L-shaped side electrode. The L-shaped side electrode is attached to a metal shell crimped about the ceramic body. At the tip of the spark plug, the center electrode protrudes from the ceramic body and is spaced apart from the side electrode to form a spark plug gap. Once the spark plug has been assembled into the engine, it is desirable to test the spark plug. In a current spark plug tester, an ignition system may be fully assembled so that the ignition coil is connected (or an ignition coil may be connected in a test stand to simulate the ignition system). When the system fires, an electromagnetic field is created around the ignition coil. This electromagnetic field may be monitored or sensed by an inductive sensor placed adjacent the coil inside the electromagnetic field. Changes in the electromagnetic field indicate changes in the spark plug gap and possibly, infrequently, may indicate a crack in a ceramic insulator. In end of line cold test machines, testing for spark plug gaps and cracked ceramic insulators may be unreliable. This potential unreliability may allow spark plugs that are out-of-specification or have a cracked ceramic insulator to remain installed in an engine causing less than optimal engine performance.